leeson



March 24, 1964 A. LEESON 3,126,459

CLOCKWORK-CONTROLLED ELECTRIC SWITCH Filed May 28, 1962 3 Sheets-Sheet 1March 24, 1964 A. LEESON 3,126,459

CLOCKWORK-CONTROLLED ELECTRIC SWITCH Filed May 28, 1962 5 Sheets-Sheet 2III/1111111".

FIG. 4. FIG. 6.

lnvenlor A Home y March 24, 1964 A. L. LEESON CLOCKWORK-CONTROLLEDELECTRIC SWITCH 3 Sheets-Sheet 3 Filed May 28, 1962 FIG. 9.

FIG. 8.

FIG. 7.

FIG. I0.

I nventor Attorney United States Patent 3,126,459 CLOCKWORK-CONTROLLEDELECTRIC SWITCH Arthur LeonardLeeson, Camber-icy, Surrey, England, as-

signor t0 Gillone Electric Limited, Camherley, Surrey, England Filed'May28, 1962, Ser. No. 199,220 Claimspriority, application Great BritainJune 1961 4' Claims. (Cl. 200-39) This invention, relates toclockwork-controlled electric switches, briefly referred to as timeswitches.

Some electric time switchescomprise spring-driven orelectricalclockworks arranged to actuate electric switches of the. kindcomprising a fixed contact and a spring-loaded moving contact whichmoves rapidly into either of two alternative rest positions in one ofwhich it is in contact with the fixed contact.

Many electric time-switches are adapted to be secured towalls ormounting boards and thus cannot be readily moved. Other electric timeswitches, which may be in the form of clocks, are adapted to standfreely on shelves or the like and are provided with trailing leads forconconnection tomain sockets and to apparatus to be controlled by theswitches; such switches can be readily moved and re-connected if thetrailing leads are fitted with suitable plugs and sockets, but thetrailing leads between the time switches and the main sockets constitutea hazard and the'time switches are easily knocked over and: damaged. Ithas also been proposed to provide a time switch with plug means wherebyit may be plugged into. aconventional socket and with socket meansadapted to receive a conventional plug.

The present invention is intended to provide an improved time switch.

According to the invention an electric time switch comprising aclockwork arranged to actuate an electric switch of the: kind referredto is characterised in that the electric switch comprises aspring-loaded pivotally-mounted catch plate capable of engaging themoving contact so as to cause the latter to move from either of its tworest positions into its other rest position, and a pawl, the arrangementbeing such that the catch-plate has two rest positions in one of whichrest positions it may be temporarily retained by the pawl and to theother of which rest positions it returns under its spring-loading whenreleased, by the pawl. The catch plate may conveniently be of a shapesomewhat like that of a hollow rectangle with a gap through which themoving contact extends, and the pawl may be pivotally mounted inside thecatch plate. Preferably the catch plate and the pawl are moved in turnby projections which move in the same direction as one another, forexample these, projections may be on arms connected to a spindle drivenby the clockwork. In an advantageous construction the time switchcomprises a timing unit and a plug unit which can be secured together orseparated from one another as required, and the plug unit comprisesconnection means of the plug type whereby it may be connected to asupply socket. This construction offers the advantage that it ispossible to make timing units which are all of one pattern and any oneof which can be fitted with a plug unit selected from a range of plugunits to suit the various supply sockets commonly in use.

Such a plug unit may comprise socket means to receive a plug connectedto an appliance, and/or such a plug unit may be provided with securingmeans for securing to the time switch one or more leads extending to oneor more electric appliances of which the electricity supply iscontrolled by the time switch. The securing means may be of any desiredconstruction, for example in the form of terminals to which wires aresecured by means of screws or nuts or by soldering, and additionally oralternatively the lead or leads may be secured by one or more clamps orby clamping between parts of a casing of the switch. The timingmechanism may be of any desired kind and may be electrically driven orspringdriven. The time switch may also incorporate a manually-operableby-pass switch by which-it is possible to close the circuit through thetime switch to an appliance while the switch actuated by the timingmechanism is open, and it may also comprise one or moretemperatureresponsive devices for operating one or more switch means.The connection means of the plug type may be of any desired size orconstruction, for example standard 13 amp, ring main or 15 amp. 3-pin or5 amp. 3-pin arrangements. The timing unit preferably comprises a casingof moulded synthetic resin or polymer from which the timing mechanismmay be easily removed; in an advantageous construction the timing unitand plug unit are secured together by means of a single screw. Furtherfeatures of the invention appear from the following description andclaims and the accompanying drawings in which a time switch according tothe invention is illustrated partly diagrammatically and by way ofexample,

FIGURES 1 and 2 being respectively front and rear perspective views ofthe time switch with one form of plug unit,

FIGURES 3 and 4 being respectively a side elevation and planof the plugunit shown in FIGURES l and 2,

FIGURES 5 and 6 being respectively a sectional elevation and underneathview of the timing unit,

FIGURES 7, 8, and 9 being respectively a plan, side elevation, andunderneath view of a modified plug unit,

FIGURE 10 being a plan of the electric switch controlled by theclockwork, and

FIGURE 11 being a view of parts which take part in the control of theswitch shown in FIGURE 10.

The illustrated time switch comprises a moulded synthetic resin casing10 accommodating a timing mechanism 19 (FIGURE 5) which can be set toactuate a switch shown in FIGURE 10 as explained below after the expiryof desired delay periods. The timing mechanism 159 comprises an electricclockwork driving a spindle 35 (FIG- URE 11), and the clockwork and theswitch. are appropriately electrically connected to sockets 4, 5 and 6(FIGURES 5 and 6) adapted to receive plug terminals 1, 2 and 3 (FIGURES3 and 4, and FIGURES 7 and 8) respectively. FIGURES 3 and 4 show a plugunit in which the plug terminals 1, 2 and 3 are mounted on a plug unitbody 11 which carries plug type connecting means in the form of pins 17adapted to be plugged into a conventional mains or like supply socket,for example a 13 amp. BA. ring main socket (not shown). When the timeswitch is assembled the plug unit body 11 is fitted to the casing 10 andis secured in place by a single screw 34- (FIGURE 2) which passesthrough a hole 29 in the plug unit body 11 and enters a tapped hole in aboss 21 secured to a mounting plate 22 which carries the timingmechanism and switch and the sockets 4, 5 and 6.

To the plug terminals 1 and 2 in the construction shown in FIGURES 3 and4 are connected two cores of a 3-core lead 13 extending to an appliance(not shown), for example, an electric room heater or immersion heater orelectric blanket or light or radio set to be automatically switched onand/ or off after the expiry of the delay periods to which the timingmechanism is set. The

third core of the lead 18 is secured by a screw 23 to that one of thethree pins 17 intended for making the earth connection, and the screw 23carries an apertured earthing strap 23. A fuse 24 is arranged betweenthat one of the three pins 17 which is the line pin and the plugterminal 3, and the latter is also provided with a bypass switch contact9. By means of a pivoted alanine manual switch knob 7 a by-pass switchcontact 3 secured to the plug terminal 2 can be moved into engagementwith the contact 9 in order to by-pass the switch actuated by the timingmechanism.

FIGURES 7 to 9 illustrate a modified plug unit which may be fitted tothe timing unit instead of the plug unit shown in FIGURES 1 to 4.

The plug unit shown in FIGURES 7 to 9 comprises a plug unit body 11 ofmodified form, carrying plug pins 17, terminals 1, 2, and 3, manualswitch knob 7, by-pass switch contacts 8 and 9, screw 23 and aperturedearthing strap 28, and provided with a hole 29 substantially as inFIGURES 3 and 4. In FIGURE 7 a connecting strap 29 takes the place ofthe fuse 24 shown in FIGURE 4. In FIGURES 7 to 9 a socket cover 25 issecured by screws 26 to the body 11 and is provided with apertures 27corresponding to socket means adapted to receive the plug pins of aconventional plug (not shown) electrically connected to an appliance(not shown). The terminals 1 and 2 and screw 23 are appropriatelyconnected by electrical leads 3th, 31, and 32 to the socket means.

FIGURE 10 illustrates the switch which is actuated by the timingmechanism. This switch comprises a support plate 36 which mayconveniently be an end plate of the electric clockwork and is penetratedby the spindle 35 driven by the clockwork. The support plate 36 carriesa pivot pin 37 on which is pivotally mounted a catch plate 38 loaded bya tension spring 3%. The catch plate 38 is of a shape somewhat like thatof a hollow rectangle with a gap between a nose 33A and corner 3813,through which gap extends a moving contact 40 pivotally mounted upon apivot pin 41 and loaded by a hairpin spring 42. The moving-contact 4G isconnected through a flexible conductor 54 to a terminal 55 which issecured to the support plate 36 and connected by a wire (not shown) tothe socket (FIG. 6). A fixed contact 45 is arranged so that it may beengaged by the moving contact 40 and is connected through a wire (notshown) to the socket 6 (FIG. 6). The hairpin spring 42 has a middle loop43 and is pivotally mounted at one end upon a pin 44 secured in thesupport plate 36, the other end of the spring 42 being formed into ahook engaging in an apertured lug formed on the moving contact 4th. Thespring 4-2. is stressed so that it presses against the moving contact 40and causes the latter to snap quickly into either of its rest positionsas hereinafter described. A pawl 46 is pivotally mounted upon a pivotpin 47 and loaded towards a tooth 38C on the catch plate 38 by a hairpinspring 4-8, the latter being supported upon the pivot pin 47 andanchored at one end to the pivot pin 37. The pawl 46 is not flat, beingcranked so that it lies partly within the plane of the catch plate 38and partly above the catch plate 38.

The switch illustrated in FIGURE is actuated by means of the timingmechanism comprising the clockwork driving the spindle 55 and the partsshown separated in FIGURE 11. Two radial arms 59 and 51 and a graduatedtiming disc 13 can be secured to the spindle 35 by means of a clampingnut 12 and a spring washer 52 by which the timing disc 13 and the radialarms 5% and 51 may be secured to the spindle in any desired relativepositions of rotation about the spindle 35. A thin disc 53 is interposedbetween the switch and the radial arms. The arm 54) has a downwardprojection 56A which follows the path indicated by the dotted line C andis capable of engaging the catch plate 38, and the arm 51 has a downwardprojection 51A which follows a path indicated by the dotted line 0 andis capable of engaging the pawl 46. The switch is shown in its openposition in FIGURE 10. When the projection StlA following the path Cengages the catch plate 38 the latter is turned about its pivot pin 37against the action of the spring 3? and the corner 35B engages themoving contact dil until the latter snaps over under the action of thespring 42 into a rest position in engagement with the fixed 4 contact45. After further slight rotation of the catch plate 38 the pawl 46urged by the spring 48 enters behind the tooth 380 so that the catchplate plate 33 is retained against movement under the action of thespring 39 by the pawl 46 engaging the tooth 38C when the projection 5ilAclears the catch plate 38.

The switch remains in the closed position so long as the pawl 46 engagesthe tooth 38C and prevents the catch plate 38 from moving under theaction of the spring 39.

When the projection 51A following the path 0 engages the pawl 46 thelatter is turned about its pivot pin 47 against the action of the spring48. When the pawl 46 has thus moved suificiently it releases the tooth38C and then the catch plate 38 turns about its pivot pin 37 under theaction of the spring 39 and the nose 38A engages the moving contact 40so that the latter snaps quickly back into the rest position shown inFIGURE 10 initially under the action of the spring 39 and finally underthe ac tion of the spring 42. I

pointers 14 and 15 which indicate against the graduations on the timingdisc 13 and there is a pointer or index mark 16 on the casing 10, seeFIGURE 1.

Assuming that the disc 13 rotates once in 24 hours and is graduatedaccordingly, the operation of setting the time switch is as follows:firstly the nut 12 (which preferably has a left-hand screw-thread) isloosened sulficiently to allow the disc 13 and arms 50 and 51 to berotated easily relatively to the spindle 35 and to each other. Then thedisc 13 is turned until the time indicated thereon by the pointer ormark 16 is the actual time at which the operation is being elfected, thepointer 14 is moved until it indicates on the disc 13 the time at whichthe switch is required to close, and the pointer 15 is moved until itindicates on the disc 13 the time at which the switch is required toopen. The nut 12 is then turned to clamp the disc 13 and arms 50 and 51to the spindle 35.

A detachable transparent cover (as shown) may be provided to cover thedisc 13 and pointers 14, 15 and 16 and the casing 10 may be providedwith a window and an internal lamp to indicate whether or not the timeswitch is connected to a source of power.

It will be readily appreciated that the invention thus provides acompact and advantageous time switch, convenient for use for example ina dwelling.

I claim:

1. A clockwork-controlled electric switch, comprising a support plate, aclockwork-rotated central spindle extending through said support plate,a first radial arm and a second radial arm both mounted on andadjustably securable to said spindle and spaced from said support plate,a fixed contact secured on said support plate, a spring-loaded catchplate pivotally mounted on said support plate and having substantiallythe form of a hollow rectangle with a gap, an internal tooth on saidcatch plate, a pawl pivotally mounted on said support plate within saidcatch plate and spring-loaded towards said tooth, a snap-action movingcontact pivotally mounted on said support plate within said catch plateand extending through said gap, a projection on said first radial arm,and a projection on said second radial arm, the arrangement being suchthat during operation said catch plate is turned against itsspring-loading by said projection on said first radial arm and movessaid moving contact until said moving contact snaps into a rest positionin engagement with said fixed contact, said pawl engages said tooth andretains said catch plate against movement, and said projection on saidsecond radial arm turns said pawl against its spring-loading forreleasing said catch plate whereupon said catch plate turns under itsspring-loading and moves said moving contact until said moving contactsnaps into a rest position remote from said fixed contact.

2. A switch as claimed in claim 1, comprising a clamping nut on saidspindle for adjustably securing said radial arms to said spindle.

3. A switch as claimed in claim 1, comprising a gradsaid clamping nutbeing tightenable for securing said uated timing disc mounted on andadjustably securtiming disc and said radial arms to said spindle in anyable Said p desired relative positions of rotation about said spindle.

4. A switch as claimed in claim 1, comprising a clamps said p g agraduated timing disc on said 5 References Cited in the file of thispatent spind e etween sai clamping nut and said radial arms, and aspring washer around said spindle between said UNITED STATES PATENTSclamping nut and said timing disc, said clamping nut 2,832,856GOOdhOIlSe P 29, 1958 being loosenable for allowing rotation of saidtiming 2,943,159 Goodhouse et al June 28, 1960 disc and said radial armsrelative to said spindle, and 10 2,996,585 Lehde Aug. 15, 1961

1. A CLOCKWORK-CONTROLLED ELECTRIC SWITCH, COMPRISING A SUPPORT PLATE, ACLOCKWORK-ROTATED CENTRAL SPINDLE EXTENDING THROUGH SAID SUPPORT PLATE,A FIRST RADIAL ARM AND A SECOND RADIAL ARM BOTH MOUNTED ON ANDADJUSTABLY SECURABLE TO SAID SPINDLE AND SPACED FROM SAID SUPPORT PLATE,A FIXED CONTACT SECURED ON SAID SUPPORT PLATE, A SPRING-LOADED CATCHPLATE PIVOTALLY MOUNTED ON SAID SUPPORT PLATE AND HAVING SUBSTANTIALLYTHE FORM OF A HOLLOW RECTANGLE WITH A GAP, AN INTERNAL TOOTH ON SAIDCATCH PLATE, A PAWL PIVOTALLY MOUNTED ON SAID SUPPORT PLATE WITHIN SAIDCATCH PLATE AND SPRING-LOADED TOWARDS SAID TOOTH, A SNAP-ACTION MOVINGCONTACT PIVOTALLY MOUNTED ON SAID SUPPORT PLATE WITHIN SAID CATCH PLATEAND EXTENDING THROUGH SAID GAP, A PROJECTION ON SAID FIRST RADIAL ARM,AND A PROJECTION ON SAID SECOND RADIAL ARM, THE ARRANGEMENT BEING SUCHTHAT DURING OPERATION SAID CATCH PLATE IS TURNED AGAINST ITSSPRING-LOADING BY SAID PROJECTION ON SAID FIRST RADIAL ARM AND MOVESSAID MOVING CONTACT UNTIL SAID MOVING CONTACT SNAPS INTO A REST POSITIONIN ENGAGEMENT WITH SAID FIXED CONTACT, SAID PAWL ENGAGES SAID TOOTH ANDRETAINS SAID CATCH PLATE AGAINST MOVEMENT, AND SAID PROJECTION ON SAIDSECOND RADIAL ARM TURNS SAID PAWL AGAINST ITS SPRING-LOADING FORRELEASING SAID CATCH PLATE WHEREUPON SAID CATCH PLATE TURNS UNDER ITSSPRING-LOADING AND MOVES SAID MOVING CONTACT UNTIL SAID MOVING CONTACTSNAPS INTO A REST POSITION REMOTE FROM SAID FIXED CONTACT.